If steaming milk is either happening too slowly or faster than you can control, you may be able to improve the experience by switching the steam tip. The larger holes a steam tip has, the quicker it will steam and froth milk. Steam tips with smaller holes tend to allow for greater user control.
What is Nuova Simonelli's Soft Infusion System (SIS) System?
SIS (Soft Infusion Systems) reduces the importance of a proper tamping technique, leading to a more consistent espresso while eliminating human error.